[tip:perfcounters/urgent] perf_counter: Log vfork as a fork event

[tip-bot for Anton Blanchard <anton@samba.org>]

Commit-ID:  ed900c054b541254f0ce5cedaf75206e29bd614e
Gitweb:     http://git.kernel.org/tip/ed900c054b541254f0ce5cedaf75206e29bd614e
Author:     Anton Blanchard <anton@samba.org>
AuthorDate: Thu, 16 Jul 2009 15:44:29 +0200
Committer:  Ingo Molnar <mingo@elte.hu>
CommitDate: Sat, 18 Jul 2009 11:21:31 +0200

perf_counter: Log vfork as a fork event

Right now we don't output vfork events. Even though we should
always see an exec after a vfork, we may get perfcounter
samples between the vfork and exec. These samples can lead to
some confusion when parsing perfcounter data.

To keep things consistent we should always log a fork event. It
will result in a little more log data, but is less confusing to
trace parsing tools.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20090716104817.589309391@samba.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>


---
 kernel/fork.c |    9 +++------
 1 files changed, 3 insertions(+), 6 deletions(-)

diff --git a/kernel/fork.c b/kernel/fork.c
index 467746b..4812d60 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1408,14 +1408,11 @@ long do_fork(unsigned long clone_flags,
 		if (clone_flags & CLONE_VFORK) {
 			p->vfork_done = &vfork;
 			init_completion(&vfork);
-		} else if (!(clone_flags & CLONE_VM)) {
-			/*
-			 * vfork will do an exec which will call
-			 * set_task_comm()
-			 */
-			perf_counter_fork(p);
 		}
 
+		if (!(clone_flags & CLONE_THREAD))
+			perf_counter_fork(p);
+
 		audit_finish_fork(p);
 		tracehook_report_clone(regs, clone_flags, nr, p);